From 82ea1815fd2c24414e207597207d185c3c646c10 Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@skiff.com>
Date: Sun, 4 Feb 2024 14:45:32 +0100
Subject: [PATCH] Refactor cache driver

---
 inc/cache.php               |   2 +-
 inc/driver/cache-driver.php | 266 ++++++++++++++++++++++++++++++++++++
 2 files changed, 267 insertions(+), 1 deletion(-)
 create mode 100644 inc/driver/cache-driver.php

diff --git a/inc/cache.php b/inc/cache.php
index c4053610..ae788bc1 100644
--- a/inc/cache.php
+++ b/inc/cache.php
@@ -25,7 +25,7 @@ class Cache {
 				self::$cache->select($config['cache']['redis'][3]) or die('cache select failure');
 				break;
 			case 'php':
-				self::$cache = array();
+				self::$cache = [];
 				break;
 		}
 	}
diff --git a/inc/driver/cache-driver.php b/inc/driver/cache-driver.php
new file mode 100644
index 00000000..b5279d82
--- /dev/null
+++ b/inc/driver/cache-driver.php
@@ -0,0 +1,266 @@
+<?php
+namespace Vichan\Driver;
+
+use RuntimeException;
+
+defined('TINYBOARD') or exit;
+
+/**
+ * PHP has no nested or private classes support.
+ */
+class CacheDrivers {
+	public static function memcached(string $prefix, string $memcached_server) {
+		$memcached = new Memcached();
+		if (!$memcached->setOption(Memcached::OPT_BINARY_PROTOCOL, true)) {
+			throw new RuntimeException('Unable to set the memcached protocol!');
+		}
+		if (!$memcached->setOption(Memcached::OPT_PREFIX_KEY, $prefix)) {
+			throw new RuntimeException('Unable to set the memcached prefix!');
+		}
+		if (!$memcached->addServers($memcached_server)) {
+			throw new RuntimeException('Unable to add the memcached server!');
+		}
+
+		return new class($memcached) implements CacheDriver {
+			private Memcached $inner;
+
+			public function __construct(Memcached $inner) {
+				$this->inner = $inner;
+			}
+
+			public function get(string $key): mixed {
+				$ret = $this->inner->get($key);
+				// If the returned value is false but the retrival was a success, then the value stored was a boolean false.
+				if ($ret === false && $this->inner->getResultCode() !== Memcached::RES_SUCCESS) {
+					return null;
+				}
+				return $ret;
+			}
+
+			public function set(string $key, mixed $value, mixed $expires = false): void {
+				$this->inner->set($key, $value, (int)$expires);
+			}
+
+			public function delete(string $key): void {
+				$this->inner->delete($key);
+			}
+
+			public function flush(): void {
+				$this->inner->flush();
+			}
+		};
+	}
+
+	public static function redis(string $prefix, string $host, int $port, string $password, string $database) {
+		$redis = new Redis();
+		$redis->connect($host, $port);
+		if ($password) {
+			$redis->auth($password);
+		}
+		if (!$redis->select($database)) {
+			throw new RuntimeException('Unable to connect to Redis!');
+		}
+
+		return new class($prefix, $redis) implements CacheDriver {
+			private string $prefix;
+			private Redis $inner;
+
+			public function __construct(string $prefix, Redis $inner) {
+				$$this->prefix = $prefix;
+				$this->inner = $inner;
+			}
+
+			public function get(string $key): mixed {
+				$ret = $this->inner->get($this->prefix . $key);
+				if ($ret === false) {
+					return null;
+				}
+				return json_decode($ret, true);
+			}
+
+			public function set(string $key, mixed $value, mixed $expires = false): void {
+				if ($expires === false) {
+					$this->inner->set($this->prefix . $key, json_encode($value));
+				} else {
+					$expires = $expires * 1000; // Seconds to milliseconds.
+					$this->inner->setex($this->prefix . $key, $expires, json_encode($value));
+				}
+			}
+
+			public function delete(string $key): void {
+				$this->inner->del($this->prefix . $key);
+			}
+
+			public function flush(): void {
+				$this->inner->flushDB();
+			}
+		};
+	}
+
+	public static function apcu() {
+		return new class implements CacheDriver {
+			public function get(string $key): mixed {
+				$success = false;
+				$ret = apcu_fetch($key, $success);
+				if ($success === false) {
+					return null;
+				}
+				return $ret;
+			}
+
+			public function set(string $key, mixed $value, mixed $expires = false): void {
+				apcu_store($key, $value, (int)$expires);
+			}
+
+			public function delete(string $key): void {
+				apcu_delete($key);
+			}
+
+			public function flush(): void {
+				apcu_clear_cache();
+			}
+		};
+	}
+
+	public static function filesystem(string $prefix, string $base_path) {
+		if ($base_path[strlen($base_path) - 1] !== '/') {
+			$base_path = "$base_path/";
+		}
+
+		if (!is_dir($base_path)) {
+			throw new RuntimeException("$base_path is not a directory!");
+		}
+
+		if (!is_writable($base_path)) {
+			throw new RuntimeException("$base_path is not writable!");
+		}
+
+		return new class($prefix, $base_path) implements CacheDriver {
+			private string $prefix;
+			private string $base_path;
+
+
+			private function prepareKey(string $key): string {
+				$key = str_replace('/', '::', $key);
+				$key = str_replace("\0", '', $key);
+				return $this->prefix . $key;
+			}
+
+			public function __construct(string $prefix, string $base_path) {
+				$this->prefix = $prefix;
+				$this->base_path = $base_path;
+			}
+
+			public function get(string $key): mixed {
+				$key = $this->prepareKey($key);
+
+				$fd = fopen("$this->base_path/$key", 'r');
+				if ($fd === false) {
+					return null;
+				}
+
+				$data = stream_get_contents("$this->base_path/$key");
+				fclose($fd);
+				return json_decode($data, true);
+			}
+
+			public function set(string $key, mixed $value, mixed $expires = false): void {
+				$key = $this->prepareKey($key);
+
+				$data = json_encode($value);
+				file_put_contents("$this->base_path/$key", $data);
+			}
+
+			public function delete(string $key): void {
+				$key = $this->prepareKey($key);
+
+				@unlink("$this->base_path/$key");
+			}
+
+			public function flush(): void {
+				$files = glob("$this->base_path/$this->prefix*");
+				foreach ($files as $file) {
+					@unlink($file);
+				}
+			}
+		};
+	}
+
+	public static function phpArray() {
+		return new class implements CacheDriver {
+			private static array $inner = [];
+
+			public function get(string $key): mixed {
+				return isset(self::$inner[$key]) ? self::$inner[$key] : null;
+			}
+
+			public function set(string $key, mixed $value, mixed $expires = false): void {
+				self::$inner[$key] = $value;
+			}
+
+			public function delete(string $key): void {
+				unset(self::$inner[$key]);
+			}
+
+			public function flush(): void {
+				self::$inner = [];
+			}
+		};
+	}
+
+	/**
+	 * No-op cache. Useful for testing.
+	 */
+	public static function none() {
+		return new class implements CacheDriver {
+			public function get(string $key): mixed {
+				return null;
+			}
+
+			public function set(string $key, mixed $value, mixed $expires = false): void {
+				// No-op.
+			}
+
+			public function delete(string $key): void {
+				// No-op.
+			}
+
+			public function flush(): void {
+				// No-op.
+			}
+		};
+	}
+}
+
+interface CacheDriver {
+	/**
+	 * Get the value of associated with the key.
+	 *
+	 * @param string $key The key of the value.
+	 * @return mixed|null The value associated with the key, or null if there is none.
+	 */
+	public function get(string $key): mixed;
+
+	/**
+	 * Set a key-value pair.
+	 *
+	 * @param string $key The key.
+	 * @param mixed $value The value.
+	 * @param int|false $expires After how many seconds the pair will expire. Use false or ignore this parameter to keep
+	 *                           the value until it gets evicted to make space for more items. Some drivers will always
+	 *                           ignore this parameter and store the pair until it's removed.
+	 */
+	public function set(string $key, mixed $value, mixed $expires = false): void;
+
+	/**
+	 * Delete a key-value pair.
+	 *
+	 * @param string $key The key.
+	 */
+	public function delete(string $key): void;
+
+	/**
+	 * Delete all the key-value pairs.
+	 */
+	public function flush(): void;
+}